How to Clean Stained Glass Windows Without Damaging Them

Quick answer: To clean stained glass windows, dust them first with a soft, dry cloth, then wipe gently with a soft cloth dampened in plain water or water with a drop of mild, pH-neutral soap. Dry right away. Skip ammonia, vinegar, abrasive pads and spray-on glass cleaners, and never press hard on bowed or loose sections. If cleaning reveals cracks, loose lead or rattling glass, have a stained glass pro take a look.

Why Stained Glass Needs Gentle Cleaning

A stained glass window isn't one sheet of glass. It's dozens or hundreds of pieces held together with lead or copper foil and solder. The glass itself is tough, but the joints and the cement that seals them aren't built to handle harsh chemicals or heavy pressure. Clean it the way you'd clean a family heirloom, because in many homes that's exactly what it is.

Here along the Front Range, dust and dry air mean windows collect a film faster than you might expect. A careful cleaning a couple of times a year keeps colors bright and gives you a chance to spot problems early.

What You'll Need

• Two or three soft, lint-free cloths (microfiber works well)
• A soft brush, such as a clean paintbrush or soft-bristled makeup brush
• A bowl of lukewarm water
• A drop of mild, pH-neutral dish soap (optional)
• Cotton swabs for corners

Step-by-Step: How to Clean Stained Glass Windows

Step 1: Check the Window First

Before you touch anything, look the panel over. Is it flat? Do any pieces move or rattle? Are there cracks? If the panel is bowing or loose, clean only very lightly or wait until it has been repaired.

Step 2: Dust Gently

Use a dry, soft cloth or brush to remove loose dust. Work along the lead lines rather than scrubbing across them. Dust that gets rubbed around with water can act like fine sandpaper.

Step 3: Wipe With Water

Dampen a cloth in plain lukewarm water and wring it out well. You want it damp, not dripping. Wipe each section gently, supporting the glass with your other hand on the opposite side if you can reach.

Step 4: Add Mild Soap Only if Needed

For greasy spots, such as a kitchen window, add a single drop of mild soap to the water. Wipe, then go over the area again with a cloth dampened in clean water so no soap is left behind.

Step 5: Dry Right Away

Use a dry cloth to pat the glass and lead dry. Standing water can work its way under the lead over time.

Do's and Don'ts

Do

• Support the panel while you clean
• Use soft cloths and light pressure
• Clean on a mild day, not when the glass is very hot or very cold
• Keep any broken fragments you find, since they help with repairs

Don't

• Use ammonia-based glass cleaners or vinegar
• Use abrasive sponges, steel wool or razor blades
• Spray liquid directly onto the window
• Use a pressure washer on the outside
• Push on bowed sections to "straighten" them

What About Painted or Antique Glass?

Some older windows have painted details fired onto the glass. Those painted areas can be more delicate. If you have an antique or historic window and aren't sure what it is, use only a dry, soft brush and ask a professional before doing more.

When Cleaning Turns Into a Repair

Cleaning is a great time for a checkup. While you're wiping, watch for:

• Cracked or missing pieces
• Lead that looks crumbly, cracked or powdery
• Light showing between the glass and lead
• Glass that rattles or moves when touched

If you find any of these, it's time for a repair visit. Steve Downing has been building and caring for stained glass since founding The Glass Master in 1989, and he'll tell you honestly whether a window needs attention now or can wait.

Serving Homeowners Across the North Metro

Our studio is in Thornton, close to Northglenn, Westminster, Broomfield, Brighton, Arvada and Denver, so if cleaning turns up a problem, help isn't far away.

Frequently Asked Questions

Can I use Windex on stained glass?

It's best to avoid ammonia-based glass cleaners. Plain water or water with a drop of mild soap is gentler on the lead and cement.

How often should I clean stained glass windows?

For most homes, a gentle cleaning once or twice a year is plenty, with occasional dusting in between. Kitchen windows may need it more often.

Can I clean the outside of a stained glass window?

Yes, gently, the same way you clean the inside. If there's protective glass over the outside, clean that like a normal window.

What if the lead looks white or chalky?

That can be oxidation. Don't scrub it hard. If it's widespread or the lead looks crumbly, have a stained glass pro look at the window.

Need a Hand With Your Stained Glass?

If cleaning shows your stained glass needs more than a wipe-down, call Steve at (303) 457-1886, 7am to 5pm daily, or send a message through our contact page. For ideas, browse our windows gallery or the full stained glass gallery.